Phoenix Contact QUINT-PS-3X400-500AC/24DC/30 2938633: Retrofit-Ready 3-Phase Power Supply for QUINT POWER Control Systems
The Phoenix Contact QUINT-PS-3X400-500AC/24DC/30 (Part No. 2938633) is a high-performance, three-phase DIN rail power supply engineered for demanding industrial control environments. Rated at 24VDC / 30A output with a wide 3-phase AC input range of 400–500VAC, this unit is a direct retrofit solution for aging QUINT POWER installations, legacy control cabinets, and distributed automation panels where reliable, uninterrupted DC power is non-negotiable.
Whether you are replacing a failed unit on a running production line, upgrading an end-of-life power section in a Siemens S7-300 or S7-400 control rack, or migrating a legacy Allen-Bradley SLC 500 panel to a modernized architecture, the QUINT-PS-3X400-500AC/24DC/30 2938633 provides the output stability, SFB (Static Boost) technology, and diagnostic signaling that system integrators and maintenance engineers depend on. Every unit supplied by SMARTNEXMSK is fully tested prior to shipment and covered by a 12-month warranty.
Upgrade Compatibility Table
| Parameter | QUINT-PS-3X400-500AC/24DC/30 (2938633) | Retrofit Notes |
|---|---|---|
| Input Voltage | 3 × 400–500VAC, 50/60Hz | Verify 3-phase supply availability at cabinet; single-phase variants (QUINT-PS-1AC) are not interchangeable |
| Output Voltage | 24VDC (adjustable 18–29.5VDC) | Match downstream 24VDC bus; check PLC I/O module and HMI panel supply tolerance |
| Output Current | 30A continuous | Audit total load: PLC CPU, I/O modules, communication modules, relays, and field devices |
| DIN Rail Mounting | 35mm DIN rail (EN 60715) | Standard TS35 rail; confirm rail depth and adjacent module clearance in existing cabinet |
| Communication / Diagnostics | Relay signal contact (DC OK), SFB boost | Wire DC OK relay to PLC digital input for remote fault monitoring; map to existing HMI alarm tag |
| Replacement Compatibility | Direct replacement for QUINT-PS-3X400-500AC/24DC/20 and similar QUINT POWER 3-phase variants | Confirm terminal pitch and wiring cross-section; 30A model may require upgraded input fusing |
| Commissioning | No firmware required; hardware only | Adjust output voltage trim pot if bus voltage deviates; verify with calibrated multimeter before energizing loads |
| Warranty | 12-Month Warranty — All units tested and verified before shipment by SMARTNEXMSK | |
Retrofit Planning for Existing Automation Systems
Successful integration of the QUINT-PS-3X400-500AC/24DC/30 2938633 into an existing control system begins with a thorough power budget audit. Before removing the legacy power supply, document the total 24VDC load drawn by all connected devices: the PLC CPU module (such as a Siemens 6ES7 315 or 6ES7 416 series processor), digital and analog I/O modules mounted on the S7-300 or S7-400 backplane, any ET 200S or ET 200M distributed I/O stations connected via PROFIBUS-DP, and field-side devices including solenoid valves, proximity sensors, and indicator lamps.
In cabinets where the original power supply fed both the PLC rack and a Siemens TP700 or TP1200 HMI panel, it is common practice to separate the HMI supply onto a dedicated QUINT-PS-1AC/24DC/10 or QUINT-PS-1AC/24DC/5 unit to reduce interdependency and simplify fault isolation. The QUINT-PS-3X400-500AC/24DC/30 2938633 then exclusively powers the control logic and I/O infrastructure, ensuring that an HMI fault cannot collapse the 24VDC bus and trigger an unplanned machine stop.
Terminal wiring is a critical step. The 2938633 uses Phoenix Contact’s standard COMBICON-style screw terminals. When replacing an older QUINT POWER unit, verify that existing cable cross-sections (typically 2.5mm² to 6mm² for 30A output circuits) are retained and that ferrules are in good condition. The input terminals accept up to 10mm² for the 3-phase AC lines; confirm that upstream MCBs or fuses are rated appropriately — typically a 16A or 20A Type C MCB per phase for a 30A output PSU at 400VAC input.
For systems using a Phoenix Contact IB IL 24 DI 16 or IB IL 24 DO 16 Inline I/O station, or a WAGO 750-series fieldbus coupler, the 24VDC supply rail must remain within ±1% during load transients. The QUINT-PS-3X400-500AC/24DC/30’s SFB technology delivers up to 150% output current for 12ms during startup surges, making it well-suited for capacitive load banks and motor starter circuits that would otherwise cause nuisance tripping on conventional power supplies.
If the retrofit involves migrating from a legacy Modicon Quantum or Modicon Premium PLC platform to a modern Schneider Electric Modicon M340 or M580 architecture, the 24VDC power infrastructure often needs to be completely redesigned. The QUINT-PS-3X400-500AC/24DC/30 2938633 is a proven choice for the new rack power section, while the existing PROFIBUS or Modbus RTU communication cabling can frequently be reused with appropriate protocol converters or gateway modules.
In multi-cabinet installations, where a master control panel feeds satellite junction boxes via 24VDC distribution, consider pairing the QUINT-PS-3X400-500AC/24DC/30 with a Phoenix Contact QUINT-BUFFER/24DC/40 UPS buffer module to maintain control power during brief mains interruptions — a common requirement in food processing, water treatment, and chemical plant environments where a controlled shutdown sequence must be executed before power loss is acknowledged by the safety PLC.
Downtime Control During System Migration
Minimizing unplanned downtime during a power supply retrofit requires a structured hot-swap or staged cutover procedure. Begin by creating a full backup of the PLC program using STEP 7, TIA Portal, or the applicable programming environment before any hardware is disturbed. For Siemens S7-300 systems, use a memory card to store the project so that the CPU can reload automatically after power restoration without requiring a laptop connection on the factory floor.
Where production schedules permit only a narrow maintenance window, pre-wire the QUINT-PS-3X400-500AC/24DC/30 2938633 on a temporary DIN rail section outside the live cabinet. Perform a bench test at rated load using a resistive load bank to confirm output voltage stability and DC OK relay operation before the scheduled cutover. This approach reduces in-cabinet work time to a simple terminal transfer and rail mounting operation, typically achievable within 30–45 minutes for a single power supply replacement.
After energizing the new unit, verify the 24VDC bus voltage at the PLC rack backplane connector, at the first and last I/O module terminal, and at the HMI panel supply input. Confirm that all PLC I/O module status LEDs return to normal, that PROFIBUS or PROFINET communication links re-establish without manual intervention, and that the HMI displays the correct process values before releasing the system to production. Log the commissioning date and output voltage reading for the maintenance record — this data supports the 12-month warranty claim process if a fault occurs within the coverage period.
For systems with safety PLCs (such as a Siemens S7-300F or a Pilz PSS 4000), confirm with the safety engineer that the power supply replacement does not invalidate the existing safety validation. In most cases, replacing a power supply with an equivalent or higher-rated unit does not require a full safety re-validation, but this must be confirmed against the site’s functional safety management plan before the system is returned to service.
Retrofit Support FAQ
Q1: Is the QUINT-PS-3X400-500AC/24DC/30 2938633 a direct replacement for the QUINT-PS-3X400-500AC/24DC/20?
A: Yes, the 2938633 (30A) is mechanically and electrically compatible with the 20A variant and mounts on the same 35mm DIN rail footprint. The higher output current rating means you must verify that upstream fusing and input cable cross-sections are adequate for the increased capacity. No firmware or software changes are required in the PLC or HMI.
Q2: What commissioning checks are required after installation?
A: After mounting and wiring, measure the output voltage at the PSU terminals and at the load end of the 24VDC distribution bus. Confirm the DC OK relay contact closes (indicating healthy output) and wire it to a spare PLC digital input if not already mapped. Check that all I/O modules power up correctly and that communication links (PROFIBUS, PROFINET, or Modbus) re-establish without errors. Record the output voltage and commissioning date.
Q3: Can this unit be used in a system with mixed 24VDC and 48VDC loads?
A: The QUINT-PS-3X400-500AC/24DC/30 2938633 is a fixed 24VDC output unit (adjustable 18–29.5VDC). It is not suitable for direct 48VDC loads. In mixed-voltage cabinets, a separate 48VDC power supply must be provided for 48VDC circuits. The 24VDC output can be used to power 24VDC control logic, I/O, and communication modules independently.
Q4: What does the 12-month warranty cover, and how is it claimed?
A: Every QUINT-PS-3X400-500AC/24DC/30 2938633 supplied by SMARTNEXMSK is tested under load before shipment. The 12-month warranty covers manufacturing defects and premature failure under normal operating conditions. To initiate a warranty claim, contact sales@smartnexmsk.com with the order reference, installation date, and a description of the fault. Replacement or repair will be arranged promptly to minimize your system downtime.
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